Portable jack



E. WOLF PORTABLE JACK Feb. 27, 11951 2 Sheets-Sheet 1 Filed Nov. 13,1945 R O T N E v m Edward wolf ATTORNEYS E. WOLF PORTABLE JACK Feb. 27,1951 2 Sheets-Sheet 2 Filed Nov. 13, 1945 INVENTOR Edward wolf mm mATTORNEYS Patented Feb. 27, 1951 UNii hD S'i'A'iiEfi @FFEQE PORTABLEJACK Edward Wolf, Stockton, Calif.

Application November 13, 1945, Serial No. 628,119

This invention relates in general to an improved portable jack of thewheel-supported type used in garages, automobile storage or parkingestablishments, or the like, for the purpose of readily and convenientlymoving automobiles from one place to another without starting the enginethereof.

In particular the present invention represents improvements over thedevice shown in U. S. Patent No. 2,254,055, dated August 26, 194d.

One object of this invention is to provide, in a portable jack whichincludes a whee supported, hand controlled frame having a jack. unit onone end thereof, novel power actuated mechanism arranged to operate thejack unit and drive the wheel supported frame along the floor, selectively.

Another object of the invention is to provide a portable jack, as above,wherein the power mechanism for operating the jack unit includes a fluidpressure actuated power cylinder coupled in novel manner to the jackunit; there being an operator-controlled fluid pressure supply systemconnected to the power cylinder whereby the operator regulates theposition of the jack unit.

A further object of the invention is to provide a portable jack, of thetype described, wh rein the drive mechanism for the wheel supportedframe includes a driven axle unit arranged to impart a semi-differentialdrive to the transversely spaced front wheels of the device so as tofacilitate manipulation thereof when said wheels are being driven.

A further object of the invention is to provide simple and inexpensivedevice, and yet one which will be exceedingly effective for the purposefor which it is designed.

These objects are a complish d by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claim.

In the drawings similar characters of reference indicate correspondingparts in the several views:

Figure 1 is a side elevation of the improved portable jack.

Figure 2 is a rear end elevation of the jack.

Figure 3 is a sectional plan view of the jack.

Figure 4 is an enlarged fragmentary cross section showing the frontwheel drive assembly.

Figure 5 is a diagram of the valve-controlled fluid pressure system forthe power cylinder.

Figure 6 is a diagrammatic plan view of modifled drive mechanism.

1 Claim. (01. 254-2) CPI Referring now more particularly to thecharacters of reference on the drawings, and at present to Figs. 1-4inclusive, the improved portable jack comprises an elongated,substantially horizontal frame, indicated generally at i; said framebeing cast in one piece and includin transversely spaced, forwardlyprojecting side beams 2, and a platform 3 at its rear end. At itsforward end the frame i is supported by a pair of transversely spacedfloor engaging wheels 6 carried on a cross shaft 5 and adapted to bedriven in the manner hereinafter described. Adjacent the forward end ofthe platform 3 the frame l is supported, on opposite sides, by outboardcaster wheels 6.

At its forward end the frame 5 supports a jack l which includes alongitudinally extending, vertically disposed parallel linkage 3pivotally supporting an automobile engaging pad 9 on its forward end.Adjacent its inner end the parallel linkage 8 is pivotally connectedbetween the side beams 2, with the uppermost one of the links in theform of a bellcrank having a depending rear leg it.

A fluid pressure actuated power cylinder H is mounted lengthwise betweenthe side beams 2 adjacent the rear ends thereof and said cylinderincludes a forwardly projecting piston rod l2. At its forward end thepiston rod is connected to a cross head unit it which includes rollers Mon opposite sides, and which rollers ride in corresponding, inwardlyfacing channels iii amxed to the innermost faces of the side beams 2whereby the cross head unit 53 is guided for movement in a substantiallyhorizontal plane. A connecting rod i6 is pivotally connected between thecross head unit it} and the lower end of the bellcrank leg iii of theparallel linkage 8.

The piston rod it of the power cylinder H is normally retracted, and atwhich time the parallel linkage a is in a down position so that theautomobile engaging pad 8 is lowered. How ever, when the cylinder H isactuated to advance the piston rod l2 and connecting rod it, the leg idis forcefully swung forwardly, resulting in upward swinging of theparallel linkage 8 and elevation of the pad e for the purpose of raisingan automobile under which the pad is disposed.

The power cylinder I i is actuated through the medium of a fluidpressure system which will hereinafter be described.

An air-cooled type, relatively small gasoline engine H is supportedabove the platform 3 by a .U- shaped pedestal it open lengthwise of thedevice, and through which pedestal a longitudinal countershaft l9extends; said countershaft being supported from the platform 3 bysuitable bearings. The countershaft IQ is constantly driven from theengine i2 by a pulley and. belt unit, indicated generally at 20; saidunit including a bottom pulley 2! fixed on the countershaft l9.

The countershaft i9 is supported for limited axial shifting movement,which is accomplished through the medium of a cam-type shifting assembly22 mounted on the rear end of the platform 3 in cooperative relation tothe corresponding end of said countershaft I9. The shifting assembly 22includes a lever 23 operative by a pull link 24 from a hand grip 25connected to the top of an upstanding, inverted U-shaped steering handle26 included in the device at its rear end.

On its face the bottom pulley 2| is formed with a friction disc 2?adapted for movement to and from driving engagement with a frictionwheel 28 slidably splined on a cross shaft 29 ahead of said bottompulley 2!. The friction wheel 28 is adjustably positioned on the crossshaft 29 by means of a shifting device 30 operated by a shifting leverassembly 3! supported in a suitable manner between forwardly anddownwardly inclined braces 32 which stabilize the handle 26.

By advance of the countershaft it through the medium of the cam-typeshifting assembly 22, the friction disc 2'! is brought into drivingengagement with the friction wheel 23, causing rotation of the crossshaft 29; such rotation being reversible by shifting said friction wheel28 to one side or the other of the axis of the friction disc 21.

The countershaft 29 is connected, in driving relation and by means of asprocket and chain unit 33, with an endless, sprocket-supported drivechain 34 which extends along one of the side beams 2 beneath a chainguard 35.

At its forward end the endless drive chain 34 extends about a sprocket38 fixed on the cross shaft inwardly of one of the wheels 4. Asemidifferential drive is provided between the shaft 5 and the wheels 4in the following manner:

A collar 37 is fixed on the shaft 5 adjacent the wheel 4 opposite thewheel corresponding to the sprocket 38, and lugs 38 project from saidsprocket and collar, respectively, for engagement with other lugs 39 onthe wheels 4. It will thus be seen that when the endless chain 34 isdriven to rotate the sprocket 35 and cross shaft 5, each of the wheels4'- is driven by engagement of the corresponding lugs 38 and 39, and yetsaid wheels may turn to right or left on the floor without any skiddingaction thereof.

The fluid pressure system for the power cylinder comprises thefollowing:

A pump 49 is mounted on the platform 3 to one side of the countershaftIS and is driven by another countershaft 4! adapted to be connected,through the medium of a. clutch 42, and sprocket and chain unit 43, withsaid countershaft if); the clutch 42 being controlled by the operatorfrom adjacent the handle 26 by means of a shifting lever assembly 44.

The piping system is shown diagrammatically in Fig. 5, and includes apressure feed conduit 45 which leads from the pump 46 to the powercylinder H; fluid being supplied to the pump 46 from a tank 46 through asupply conduit 41. The tank 46 may be located at any convenient point onthe device, and in the present embodiment is suspended beneath theplatform 3.

Upon operation of the pump, fluid under pressure feeds through theconduit 45, including a check valve 48 interposed therein, and thencepasses to the cylinder H in actuating relation to the same, causingelevation of the jack unit in the manner previously described. When thepump stops the check valve 48 closes and the jack unit remains elevateduntil the cylinder l I is released, as follows:

A relief conduit 69 leads from the conduit between the check valve 48and cylinder H to connection with the supply conduit 41 between the pumpll] and tank 46; there being a normally closed hand valve 59 interposedin the relief conduit 49. The hand valve 50 is controlled by a handlever B! disposed adjacent the handle 26. When the cylinder H has beenactuated to raise the jack unit, it can thereafter be released bybleeding back the pressure therefrom through the relief conduit 49 uponopening of the hand valve 50, whereupon the fluid pressure delivers backto the tank 46.

To summarize, the above described portable jack is manipulated by anoperator as follows:

The operator grasps the upstanding handle 25 and rolls the device underan automobile until the pad 9 is in correct position. Thereafter theshifting iever assembly i l is operated to cause driving of the pump 10,with resultant raising of the jack unit to desired height, whereupondrive of the pump is stopped by release of the clutch 42. Thereafter thehand grip 25 is operated to cause driving engagement between thefriction disc 22' and friction wheel 28, the latter having first beenset in forward or reverse driving direction. The drive is then impartedto the front wheels 4, in a direction to move the jackedup automobile.Steering of the portable jack, and the automobile supported thereby, isaccomplished by the operator through manipulation of the handle 28.

In Fig. 6 there is illustrated a modification of the drive which may beemployed between the engine and the sprocket and chain unit 33 In thisembodiment the engine drives a pulley 5! on an axially immovablecountershaft 52 journaled on the platform. Between the pulley 5! and thesprocket and chain unit 33 there is interposed a manually engageableclutch adjacent the pulley 5i, and a bevel-gear type reversing unit 5 3is connected between said clutch and the sprocket and chain unit 33. Thepump as would be driven from the countershaft 52 in the same manner asit is now driven from the countershaft I9, including a sprocket andchain unit 55 and a manually engageable clutch 56.

From the foregoing description it will be readily seen that there hasbeen produced such a device as substantially fulfills the objects of theinvention, as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetails may be resorted to as do not form a departure from the spirit ofthe invention, as defined by the appended claim.

Having thus described the invention, the following is claimed as new anduseful and upon which Letters Patent are desired:

A portable :Eack comprising an elongated wheel supported frame, anengine on said frame, a clutch controlled means for selectively placingcertain of the wheels supporting the frame in or out of driving relationwith the engine whereby to allow the frame to be driven from point topoint, an upstanding rigid steering handle on the frame at one endthereof, a lift jack unit on the frame at the opposite end thereof. afluid pressure actuated power cylinder mechanism connected in operativerelation with the jack to effect the raising of the jack when pressureis admitted to the cylinder, and a fluid pressure system for supplyingfluid under pressure to said cylinder, such system comprising a pump,clutch centre d means for selectively placing the pump in out of drivingrelation w th the engine, a fluid supply reservoir, a condr t lcadingfrom the reserve-1r to the intake side oi the pump, a conduit leadingfrom the outlet side of the pump to the power cylinder, a check valve inthe latter conduit operative to pr vent hack pressure from the cylinderthrough the pump, a third conduit leading from the second named conduitat a point between the cylinder and check valve and. hence to thereservoir, a con trol valve in the third named conduit which valve maybe normally maintained in closed position while th pump is connected indriving relation with the engine and after disconnection therewith, andwhile the jack is in raised position, whereby to hold. the jack inraised position while allowing the engine to be then conn cted indriving relation with the driven wheels to transport any objectsupported on the jack from point to point with the travel of the frame,a

6 manually operable lever connected in operative relation to the controlvalve and extending to a position adjacent the steering handle, and aseparate operating means for the respective clutch controlled means andeach including an operating handle disposed adjacent the steeringhandle.

EDWARD WOLF.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 15 Number Name Date 99,56? Haussknecht Feb. 8,1870 1,232,949 Hollis Apr. 9, 1918 1,895,583 Manley May 19, 19311,813,429 Sexton July '7, 1931 1,953,670 Cochin Apr. 3, 1934 2,254,055Wolf Aug. 26, 1941 2,299,159 Kennedy Oct. 20, 1942 2,384,059 Wolf Sept.4, 1945 FOREIGN PATENTS N umber Country Date 442,148 Great Britain Feb.3, 1936

